What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Cabinets are one of the must-have furniture in home improvement homes. They are extremely useful. Various cabinets may be used in kitchens, bathrooms, bedrooms, living rooms, and even balconies. The traditional cabinets are assembled in advance and then placed in the appropriate position, which is very inconvenient to transport. Currently, the commonly used cabinets are spliced together with plates and hardware accessories. During production and transportation, the plates and hardware accessories are independent. For production, processing and transportation, after it is sent to the destination, it is assembled with the plates by screws and other hardware accessories to form the entire cabinet structure. The current cabinet installation structure usually exposes some hardware accessories such as screws on the outside or inside of the cabinet, which not only affects the overall aesthetics, but also scratches the items during use, which affects the use effect. Some designs allow a plastic fastener to be fastened on the outside of hardware accessories (mainly screws). Although it can alleviate the above problems to a certain extent, it still does not fundamentally solve the problem, and the integrity is still not good.
China is the world's largest producer of carbon steel fasteners such as screws, nuts and bolts, and the EU is a major market for these products. In January 2009, the EU decided to impose anti-dumping duties of 26.5% to 85% on Chinese carbon steel fastener products. On July 31 of the same year, China resorted to the relevant EU legislation and anti-dumping measures to the WTO dispute settlement mechanism. The case became China's first lawsuit against the EU at the WTO. On July 15, 2011, the WTO Appellate Body issued a report and finally ruled that China won the case in the trade dispute with the European Union on fasteners. The head of the Department of Treaty and Law of the Ministry of Commerce of China welcomed the ruling on the 16th, and said that China's victory in the case is of great significance, which will help improve the competitive environment for Chinese companies in the international market including the European Union, and will also strengthen the WTO members' interest in the case. Confidence in WTO rules and the multilateral trading system. This is not only a victory for China's industry, but also a victory for WTO rules, the official said. The WTO Appellate Body found in its ruling report issued on the 15th that Article 9(5) of the EU's Basic Anti-dumping Regulations on individual tax rates violated WTO rules; at the same time, the Appellate Body overturned some of the panel's rulings and supported China's position , ruled that the EU's anti-dumping measures against Chinese screws, nuts, bolts and other carbon steel fasteners also violated WTO rules in terms of domestic industry identification, normal value and fair comparison of export prices. The head of the Treaty and Law Department of the Ministry of Commerce of China said that the EU is one of the WTO members that has initiated the most anti-dumping investigations against Chinese products in the world. unfair treatment. He said that China hopes that the EU will cancel the legislation and discriminatory anti-dumping measures that are inconsistent with WTO rules as soon as possible, treat Chinese export enterprises fairly, and effectively safeguard free trade and fair competition.
In order to solve the above-mentioned technical problems, the technical solution adopted by Guangdong Yueluo Hardware Industry Co., Ltd. is: shear rivets, including a mandrel and a deformation sleeve ring sleeved on the mandrel, one end of the deformation sleeve ring is a boss structure, and the It includes an adhesive collar sleeved on the deformation collar, the adhesive collar is a hollow annular sleeve and is filled with adhesive material; one end of the mandrel is a hemispherical head, and the spherical surface of the hemispherical head is outward, The connection between the hemispherical head and the mandrel is a conical connecting section, and the diameter of the conical connecting section gradually decreases from the hemispherical head inward; the mandrel is provided with a stress concentration groove, and the position of the stress concentration groove is close to the deformation The boss structure of the collar.
Existing wood screws are composed of a threaded portion with a tapered angle and arranged along a tapered stem and a screw head. The head of the screw can be a countersunk head, hemispherical, or other shapes, and the head of the screw has a groove that fits with the tool, a word groove, and a concave cross groove. The taper angle of existing wood screws is either 45 degrees or 60 degrees, and the front end of the taper angle is a pointed point formed by a rotating thread. The existing wood screws have the following three deficiencies in use. Because the taper angle is 45 degrees or 60 degrees, and the thread angle is 71 degrees, the resistance when entering the material is relatively large, so the existing wood screws are manually screwed. It is difficult to screw in, especially when it is used for hardwood materials, and it often happens that the groove of the screw head is screwed out; A large lateral moment will be formed when the screw is screwed, which is prone to the problem of deviation from the position; in addition, because the existing screw is tapered, it will be subjected to both radial force and axial force when entering the material, and its stress state It is more complicated, so it is easy to cause the cracked wood material to burst, and even cause the material to have longitudinal cracks and be unusable.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
